Routers with detachable motors and switch handles



July 8, 1958 E. P. TURNER ET AL 2,842,173

ROUTERS WITH DETACHABLE MOTORS AND SWITCH HANDLES Filed June 27, 1956 3 Sheets-Sheet l A '0 NEY July 8, 1958 E. P. TURNER ET AL 2,842,173

ROUTERS WITH DETACHABLE MOTORS AND SWITCH HANDLES Filed June 27, 1956 v s Sheets-Sheet 2 INVENTORSL Edgar P, Turner and BY Reynold Happe TTORNE Y July 8,1958 5 E. P. '\I"URNER ETAL 2,842,173,v

ROUTERS WITH DETACHABLE MOTORS AND SWITCH HANDLES Filed June 27, 1956 3 Sheets-Sheet 3 I INVENTORS.

Edgar P. Turner and Y Reynold Happe A TORNE-Y 69 W fi' -n Unite States ROUTERS WITH DETACHABLE MUTORS AND SWITCH HANDLES Application June 27, 1956, Serial No. 594,207

11 Claims. (Cl. 144-436) This invention relates to a motor-driven router having a quickly detachable electric motor and separate detachable grip handle containing a control switch.

More especially this invention relates to means for readily and accurately adjusting the router for predetermined depth of out while preserving the quick detachability of the motor and handle.

The use of power tools in the home has been greatly expanded in recent years and the number and variety of such tools is on the increase. In the interest of economy it is desirable that a single motor unit be adaptable for driving several different tools. This has been accomplished in the prior art generally by the use of special attachments for a primary tool, usually a portable drill, but has not been entirely satisfactory because the proper and safe handling of the adapted tool is usually different from the primary tool and, due to the mechanically fixed relation between the switch and the motor, this may be impossible.

This difiiculty has been remedied according to this invention by providing a detachable control handle with switch as an element mechanically separate from the detachable motor so that both elements may be independently secured on the tool body in the position most convenient and safe for handling the particular tool.

It is a primary object of this invention therefore to provide a motor-driven router having structure affording a separately detachable but electrically connected motor and control handle with switch.

atent o to permit waste chips to be expelled. Secured to the base 10 on opposite sides is a knob 15 and a detachable control handle 16 containing a switch 17 with a trigger actuator 18 shown best in Fig. 8. This arrangement provides for natural two-hand guiding of the tool with the A further object of this invention is to provide a simple adjusting mechanism for a router including indexing means for speedily and accurately setting the cutter with respect to the desired depth of cut and without adversely affecting the'quick detachability of the motor.

With the above and other objects in view, as will here inafter appear, the invention comprises the devices, combinations, and arrangements of parts hereinafter set forth and illustrated in the accompanying drawings of a preferred embodiment of the invention, from which the several features of the invention and the advantages attained thereby will be readily understood by those skilled in the art.

In the drawings, Fig. 1 is a vertical section, partly in elevation, taken through a router embodying the invention. Fig. 2 is a top plan view, partly in section, of the device of Fig. 1. Fig. 3 is a bottom plan view of the device of Fig. 1. Fig. 4 is a detail plan view in section of aportion of Fig. 2 showing an important relation of the parts. Fig. 5 is a detail vertical section taken on the line 55 of Fig. 4. Fig. 6 is a side elevational view of the control handle. Fig. 7 is a general view of the parts in detached position. Fig. 8 is a side elevational view of the control handle with one of the split halves removed.

Referring to Fig. 1, a router base 10, preferably made of cast aluminum alloy, is in the form of a hollow cylindrical shell 11 with a flanged base 12 for support on the material to be worked. Cut-out side portions 13 are provided in the base for visual access to a cutter 14 and switch trigger always under the operators finger and available for instant control.

The inner wall 19 of the base 10 is cylindrical and smooth except for a single vertical slot 20 and a peripheral shoulder 21 formed in the end opposite the flanged end. The vertical wall 22 of the shoulder 21 is formed with a continuous annular groove 23. Also formed in this end of the base is an annular groove 24 open to the top surface.

A flanged annular ring 25 seated on the shoulder 21 is free to rotate relatively to the base 10, has an inner cylindrical wall 26 flush with the inner wall 19 of the base and is smooth except for a single vertical slot 27 which may be placed in register with the slot 20.

An electric motor 28 has an end cover 29 and a cylindrical outer case 30 which latter is snuglyslidable within the router base 10. The motor has a splined shaft extension 31 at the lower end to which is secured a chuck 32 for holding 'a suitable cutter 14. Three equally axially spaced and pitched helical grooves 33 are cut into the outer periphery of the motor case 30. Three radial pins 34 secured to the annular ring 25 at equal angles around the periphery have their outer ends in slidable engagement with the single annular groove 23. Each pin 34 has its inner end in slidable engagement with a respective one of the helical grooves 33 In this manner the ring 25 is free to rotate in the shoulder 21 but is held captive in the base 10 and cannot be dislodged axially because of the pin engagement with the annular groove 23. At the same time, due to the pin engagement with the helical grooves 33, rotation of the ring imparts a vertical axial movement to the motor case 30 which is prevented from rotating by a pin 35 secured in the case 30 and engaging the vertical slot 20 in the router base 10. It is quite important and unusual in routers that the motor case remain non-rotatable because the connecting lead to the motor can then be dressed to the best position for easy and safe manipulation of the tool and it will remain that way as compared with the random and movable position of this lead in routers with rotatable motor cases.

A movable index element 36 of spring material is formed with a flat tab portion 37 which is sprung to lie within the annular groove 24 with which it is thus frictionally coupled to permit positional adjustment of the element around the periphery of the ring 25. The index element 36 has an external portion 38 which is bent around the flanged portion of the ring 25 and terminates in a pointer 39 which overlies the top surface of the ring 25 to cooperate with a scale 40 marked thereupon.

Secured within the end cover 29 and case 30 is a series-commutator electric motor having a stator core .41, brushholders 42 and brushes 43 arranged in conventional fashion. A rotor 44 with commutator 45 is mounted on a shaft 46 journaled in bearings 47 and 48. A fan .49 carried by the shaft 46 provides ventilation for the motor by drawing air in through apertures 50 and 51 (Fig. 2) in the end cover 29 and exhausting it through apertures 52 and 53 (Fig. 3) in the end of the motor case where it is instrumental in blowing chips away from the cutter 14.

A chuck 32 is formed with a split body portion 54 having a splined aperture to fit the splined portion 31 of the shaft to which it is secured by taking up on a clamping screw 55 as seen best in Figs. 1 and 3. Bayonet slots 56 may be formed in the end of the motor case 30 and may be backed up by internal detent springs 57 to facilitate mounting of the motor in another tool Patented July 8, 1958" body by engagement with suitable headed pins for example.

A knurled knob 53 is formed with a shank portion 59 threaded into a hollow boss 60 formed on the outer wall of the router base 10 as seen best in Fig. 2. A hexagonal pressure member 61 is slidable in a hexagonal radial aperture 62 to reach through the aperture to contact the motor case 36 in frictional engagement, said pressure member having a concave face 63 shaped to conform to the cylindrical motor case 36. A reduced cylindrical shank portion 64 of the pressure member 61 extends through a central aperture in the knob and is retained therein by a washer 65 secured by a drive pin 66. Nylon plugs 67 are seated in radial bores made in the threaded shank portion 59 of the knob and engage the internal threads of the boss 60 to serve as frictional locking members to prevent loosening of the knob 58 and thus prevent reduction of holding pressure due to vibration of the cutter 14. This pressure device is used to lock the motor case 30 and thus position the cutter l4 vertically relatively to the router base it} after a proper depth of cut adjustment has been made by rotating the ring 25 relatively to the pointer 39.

Formed in the flanged portion 12 of the base 10 is a tapered dovetailed rib 63 adapted to engage a mating slot 69 formed in the split handle 16. A thumb-screw 7t} threaded into an insert 71 in the handle 16 engages a notched portion 72 of the rib 68 to provide locked securement.

it will be seen in Fig. 7 that, when detached from the router base, the motor 28 and handle 16 are completely independent units joined by a flexible electric cable 73 and have a power plug 74 and cable 75 for connection to an electrical outlet. If, for example, it is desired to use this same motor in a different tool body, say a planer, the motor may be attached in the most convenient position and the handle also may be attached in its most convenient position for a planer quite independently from the motor and in different relative positions if need be than was the case with the router. In other words, with this flexible arrangement the best and safest possible mounting positions for motor and handle are instantly available for each tool body, and use in one tool body imposes no restrictions on the subsequent use in another tool body.

The control handle 16 being split facilitates the wiring assembly as shown clearly in Fig. 8 which is a view with one of the halves removed. The use of push-on connectors 78 frictionally held on the lugs 79 of the switch 17 and the insulated wire nut 80 eliminates the need for soldering. A grounding screw 81 provides positive grounding of the handle 16 and also serves as a convenient tie point for the ground lead 82 on its way to the motor frame. Strain relief bushings 83 and 84 are fitted into notches in the split halves. 17 is located by pins 85 which seat in recesses 86 and securement is completed by putting on the cover half to engage the lock button 87 which is secured to the switch.

It will be noted from Figs. 4 and 5 that there is a single radial aperture 76 in the router base 10 located in a common plane with the annular groove 23. It is through this aperture 76 that the three pins 34 are in serted for driving into the ring 25 during assembly, the ring 25 being rotated through an angle of degrees for each pin insertion. The helical grooves 33 have the bottom wall relieved or discontinued at a predetermined point 77 short of the bottom of the motor case 30. When the ring 25 is turned to raise the motor 23 preparatory to removal from the router base 10, the respective pins 34 run into this relieved portion of each groove 33 coincidentally with the alignment of the slot 27 in the ring 25 with the slot 20 in the base 10 so that the motor case 30 is free for removal from the base 10 by a straight vertical lift. Contrariwise, when attaching the The switch motor to the router base, it is only necessary to align the grooves 20 and 27 and the pin 35, set the motor down within the base 10 and rotate the ring 25.

It will be evident from the above that there is provided according to this invention a structure for a motordriven router which has considerable advantages from the standpoint of easy, accurate adjustability for depth of cut together with ready detachability of motor and control handle for use in other tools requiring the same or difierent relative positions for best and safest appli- CitilS-ll.

Having thus set forth the nature of the invention, what We claim herein is:

l. in a router having a hollow cylindrical shell formed l a flanged. base for contact with the work, an elecmotor having a cylindrical outer case slidable axially within said router shell, equally spaced and pitched helical grooves formed into the outer periphery of the motor case, a single annular groove formed in the inner wall of the router shell, an annular index ring coaxially seated within one end of the shell adjacent the annular groove and rotatable relatively to the shell, radial pins secured in said index ring and spaced about the ring periphery, each of said pins engaging with a respective one of the helical grooves in the motor case and all of said pins engaging the single annular groove in the router shell, means for locking the motor case against rotation relative to the router shell, and separate means selective for locking the motor case against movement in an axial direction relative to the router shell.

2. in a motor-driven router, a hollow cylindrical shell formed with a flanged base for contact with the work, a demountable electric motor formed with an outer cylindrical case slidably received in coaxial engagement with the shell and carrying at one end a power take-off shaft to which is secured a holder for a cutter, means for preventing rotation of the motor ease relative to the shell, and means for adjusting in an axial direction the position of the motor case relative to the shell including an annular rotatable ring captive in the cylindrical shell and surrounding the motor case, helical grooves formed in the outer wall of the motor case, and radially positioned pins secured in the annular ring and projecting into the helical grooves so that rotation of the ring imparts a linear motion to the motor case relative to and along the axis of the cylindrical shell.

3. A motor-driven router according to claim 2 in which the annular ring carries scale markings, and an index pointer captive in an annular groove in the shell is movable relatively to both the ring and the shell to establish an arbitrary zero depth setting for the cutter.

4. In a motor-driven router, a vertically positioned hollow cylindrical shell formed at one end with a flanged base for contact with the work, an electric motor having an outer cylindrical case restricted to slide vertically within the router shell, grooves formed in the outer wall of the motor case defining three axially interspaced helices, an annular shoulder formed in the inner wall of the shell at the end opposite the flanged base, an annular ring rotatably seated on the shoulder, a single annular groove formed in the shell wall contiguous to the annular ring, and pins secured in the ring and extending radially therethrough with their outer ends in sliding engagement with the single annular groove and their inner ends in sliding engagement with a respective one of the helices so that rotation of the ring imparts linear vertical motion to the motor case relative to the shell.

5. A motor-driven router comprising a hollow cylindrical shell formed at one end with a flanged base for contact with the work, an electric motor having an outer cylindrical case locked against rotation relative to the shell but normally slidable within the shell and selectively removable therefrom, a control handle removably secured to the flanged base, a trigger-controlled switch mounted in the handle, and a current-conducting cable electrically connecting the switch with the motor and with a plug for selective connection to a source of electric power.

6. In a motor-driven router having a hollow cylindrical shell formed with a flanged end for contact with the work, an electric motor having an integral outer cylindrical case fitted to slide coaxially within said router shell, means for at all times preventing rotation of the motor case relative to the shell, an adjustable ring captive in said shell to rotate coaxially therewith, axially interspaced helical grooves of equal pitch formed in the motor case, radial pins carried by the ring and spaced at equal angles about the periphery of the ring, each pin being in sliding engagement with a respective helical groove whereby rotation of the ring imparts a linear coaxial movement to the motor case relative to the router shell, and selective means for frictionally locking the motor case to the router shell.

7. In a motor-driven tool having a body portion, an electric motor releasably secured to the body portion, a control handle separate from the motor and releasably secured to the body portion, an electric switch built into the handle, a power plug, a flexible wiring harness permanently interconnecting the motor, the switch and the power plug to form a controllable power unit for selective use with other tool bodies by quick release from the present tool body and ready attachment to other tool bodies.

8. In a motor-driven router having a hollow cylindrical shell presenting a smooth inner wall, an electric motor formed with an integral outer cylindrical case slidable axially within the router shell, an annular ring captive in the shell and rotatable relatively thereto, scale markings carried by the ring, inclined grooves formed in the outer surface of the motor case, pin means secured to the ring and engaging the grooves in slidable relation, means for at all times preventing rotation of the motor case relative to the router shell, and pointer means frictionally coupled to the router shell and movable relatively to the annular ring for establishing an index for cooperation with the scale markings to determine the extent of the rotational movement of the annular ring relative to the router shell.

9. In a motor-driven router having a hollow cylindrical shell body, an electric motor having an outer cylindrical case receivable in detachable coaxial engagement with the router shell body, a control handle containing a trigger switch, a power plug, current-conducting cables connecting the control handle to the motor and to the power plug, and means for detachably securing the control handle to the router shell body.

10. in a motor-driven tool, a demountable electric motor, a separate demountable control handle, an electric switch built into the handle, a power plug, a wiring harness permanently interconnecting the motor, the switch and the power plug to form a flexible power and control unit for selective use in other tools.

11. In a motor-driven router, a hollow cylindrical shell formed with a flanged base for contact with the work, a demountable electric motor formed with an integral outer cylindrical case slidably received in coaxial engagement with the shell and carrying at one end a power takeofl? shaft to which is secured a holder for a cutter, means for at all times preventing rotation of the motor case relative to the shell, an annular rotatable ring captive in the cylindrical shell and surrounding the motor case, and slidably coacting helical means connecting the motor case and the annular ring for adjusting in an axial direction the position of the motor case relative to the, shell by rotation of the annular ring.

References Cited in the file of this patent UNITED STATES PATENTS 1,532,683 Carter Apr. 7, 1925 1,745,780 Casey Feb. 4, 1930 1,899,883 Sacrey Feb. 28, 1933 2,562,143 Godfrey et a1. July 24, 1951 2,702,569 Yelle Feb. 22, 1955 2,756,785 Godfrey July 31, 1956 

